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<div class="titlepage"><div><div><h5 class="title">
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy"></a><a class="link" href="closest_points_4_with_strategy.html" title="closest_points (with strategy)">closest_points
          (with strategy)</a>
</h5></div></div></div>
<p>
            <a class="indexterm" name="idm27940"></a>
Calculate the closest points between two geometries using the specified
            strategy.
          </p>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h0"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.description"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.description">Description</a>
          </h6>
<p>
            The free function closest_points calculates the distance between two
            geometries using the specified strategy. Reasons to specify a strategy
            include: use another coordinate system for calculations; construct the
            strategy beforehand (e.g. with the radius of the Earth); select a strategy
            when there are more than one available for a calculation.
          </p>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h1"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.synopsis"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.synopsis">Synopsis</a>
          </h6>
<p>
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Geometry2</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Segment</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Strategy</span><span class="special">&gt;</span>
<span class="keyword">void</span> <span class="identifier">closest_points</span><span class="special">(</span><span class="identifier">Geometry1</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">geometry1</span><span class="special">,</span> <span class="identifier">Geometry2</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">geometry2</span><span class="special">,</span> <span class="identifier">Segment</span> <span class="special">&amp;</span> <span class="identifier">shortest_seg</span><span class="special">,</span>
                    <span class="identifier">Strategy</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">strategy</span><span class="special">)</span></pre>
<p>
          </p>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h2"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.parameters"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.parameters">Parameters</a>
          </h6>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                    <p>
                      Type
                    </p>
                  </th>
<th>
                    <p>
                      Concept
                    </p>
                  </th>
<th>
                    <p>
                      Name
                    </p>
                  </th>
<th>
                    <p>
                      Description
                    </p>
                  </th>
</tr></thead>
<tbody>
<tr>
<td>
                    <p>
                      Geometry1 const &amp;
                    </p>
                  </td>
<td>
                    <p>
                      Any type fulfilling a Geometry Concept
                    </p>
                  </td>
<td>
                    <p>
                      geometry1
                    </p>
                  </td>
<td>
                    <p>
                      A model of the specified concept
                    </p>
                  </td>
</tr>
<tr>
<td>
                    <p>
                      Geometry2 const &amp;
                    </p>
                  </td>
<td>
                    <p>
                      Any type fulfilling a Geometry Concept
                    </p>
                  </td>
<td>
                    <p>
                      geometry2
                    </p>
                  </td>
<td>
                    <p>
                      A model of the specified concept
                    </p>
                  </td>
</tr>
<tr>
<td>
                    <p>
                      Segment &amp;
                    </p>
                  </td>
<td>
                    <p>
                      Any type fulfilling a Segment Concept
                    </p>
                  </td>
<td>
                    <p>
                      shortest_seg
                    </p>
                  </td>
<td>
                    <p>
                      Output segment containing the closest points
                    </p>
                  </td>
</tr>
<tr>
<td>
                    <p>
                      Strategy const &amp;
                    </p>
                  </td>
<td>
                    <p>
                      Any type fulfilling a Closest Points Strategy Concept
                    </p>
                  </td>
<td>
                    <p>
                      strategy
                    </p>
                  </td>
<td>
                    <p>
                      The strategy which will be used for closest_points calculations
                    </p>
                  </td>
</tr>
</tbody>
</table></div>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h3"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.header"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.header">Header</a>
          </h6>
<p>
            Either
          </p>
<p>
            <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
          </p>
<p>
            Or
          </p>
<p>
            <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">closest_points</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
          </p>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h4"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.example"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.example">Example</a>
          </h6>
<p>
            Shows calculation of the two closest points between two geometries using
            strategies
          </p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>

<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">linestring</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">multi_point</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span>
        <span class="special">&lt;</span>
            <span class="keyword">double</span><span class="special">,</span>
            <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">cs</span><span class="special">::</span><span class="identifier">geographic</span><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">degree</span><span class="special">&gt;</span>
        <span class="special">&gt;</span> <span class="identifier">point_type</span><span class="special">;</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">polygon_type</span><span class="special">;</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">linestring</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">linestring_type</span><span class="special">;</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">multi_point</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">multi_point_type</span><span class="special">;</span>

    <span class="identifier">point_type</span> <span class="identifier">p</span><span class="special">(</span><span class="number">4.3</span><span class="special">,</span><span class="number">1.9</span><span class="special">);</span>
    <span class="identifier">polygon_type</span> <span class="identifier">poly</span><span class="special">;</span>
    <span class="identifier">linestring_type</span> <span class="identifier">line</span><span class="special">;</span>
    <span class="identifier">multi_point_type</span> <span class="identifier">mp</span><span class="special">;</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">strategies</span><span class="special">::</span><span class="identifier">closest_points</span><span class="special">::</span><span class="identifier">geographic</span><span class="special">&lt;&gt;</span> <span class="identifier">strategies</span>
        <span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">srs</span><span class="special">::</span><span class="identifier">spheroid</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;(</span><span class="number">6378137.0</span><span class="special">,</span> <span class="number">6356752.3142451793</span><span class="special">));</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span>
        <span class="string">"POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3)"</span>
            <span class="string">"(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))"</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">);</span>

    <span class="identifier">line</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">point_type</span><span class="special">(</span><span class="number">5</span><span class="special">,</span><span class="number">0</span><span class="special">));</span>
    <span class="identifier">line</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">point_type</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">0</span><span class="special">));</span>
    <span class="identifier">mp</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">point_type</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">0.5</span><span class="special">));</span>
    <span class="identifier">mp</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">point_type</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">3</span><span class="special">));</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">segment</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">sout1</span><span class="special">,</span><span class="identifier">sout2</span><span class="special">,</span><span class="identifier">sout3</span><span class="special">;</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closest_points</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">,</span> <span class="identifier">sout1</span><span class="special">,</span> <span class="identifier">strategies</span><span class="special">);</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Point-Poly: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">wkt</span><span class="special">(</span><span class="identifier">sout1</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closest_points</span><span class="special">(</span><span class="identifier">poly</span><span class="special">,</span> <span class="identifier">line</span><span class="special">,</span> <span class="identifier">sout2</span><span class="special">,</span> <span class="identifier">strategies</span><span class="special">);</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Poly-Line: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">wkt</span><span class="special">(</span><span class="identifier">sout2</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>

    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">closest_points</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">mp</span><span class="special">,</span> <span class="identifier">sout3</span><span class="special">,</span> <span class="identifier">strategies</span><span class="special">);</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Poly-MultiPoint: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">wkt</span><span class="special">(</span><span class="identifier">sout3</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>

    <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
</pre>
<p>
          </p>
<p>
            Output:
          </p>
<pre class="programlisting">Point-Poly: LINESTRING(4.3 1.9,4.20096 2.1005)
Poly-Line: LINESTRING(2.9 0.7,2.9 0)
Poly-MultiPoint: LINESTRING(4.3 1.9,2 3)
</pre>
<h6>
<a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.h5"></a>
            <span class="phrase"><a name="geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.see_also"></a></span><a class="link" href="closest_points_4_with_strategy.html#geometry.reference.algorithms.closest_points.closest_points_4_with_strategy.see_also">See
            also</a>
          </h6>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
                <a class="link" href="../distance.html" title="distance">distance</a>
              </li></ul></div>
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<td align="right"><div class="copyright-footer">Copyright © 2009-2021 Barend Gehrels,
      Bruno Lalande, Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its affiliates<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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